The alpha-fibrous proteins of cow snout have been isolated and the changes occuring during keratinization identified. The polypeptide chains of the extracted proteins will be purified in sufficient quantities to permit investigation of their physiochemical properties. It will be determined if the polypeptide chains are components of the helical protein or whether there is a matrix component. Studies of patients with keratinizing disorders will be continued and an investigation of the fully keratinized tissues will be undertaken. Further studies of the polypeptide chains of normal hair proteins as well as the variant polypeptides which have been observed will be carried out. Similar studies of nail proteins will also be performed.